The elastic potential energy of a spring is given by

where k is the spring's constant and x is the displacement with respect to the relaxed position of the spring.
The work done by the spring is the negative of the potential energy difference between the final and initial condition of the spring:

In our problem, initially the spring is uncompressed, so

. Therefore, the work done by the spring when it is compressed until

is

And this value is actually negative, because the box is responsible for the spring's compression, so the work is done by the box.
Answer:
For areas marked X, Y, Z, X is attractive only, Y has a very small range, and Z is attractive and repulsive
Explanation:
Solution
Given that:
From the question stated, Anna drew a diagram to compare forces that are strong and weak.
Now,
We are to find which labels are grouped in areas marked as X, Y, Z respectively.
Thus,
For X, Y, Z it is marked as:
X: Always attractive or attractive only
Y: Very small range
Z: Repulsive and attractive
Answer:
1 angstrom = 0.1nm
5000 angstrom = 5000/1 × 0.1nm
<h3>= 500nm</h3>

5000 angstrom = 5000 × 1 × 10^-10
<h3>= 5 × 10^-7 m</h3>
Hope this helps you
Answer:
The frequency is 302.05 Hz.
Explanation:
Given that,
Speed = 18.0 m/s
Suppose a train is traveling at 30.0 m/s relative to the ground in still air. The frequency of the note emitted by the train whistle is 262 Hz .
We need to calculate the frequency
Using formula of frequency

Where, f = frequency
v = speed of sound
= speed of passenger
= speed of source
Put the value into the formula


Hence, The frequency is 302.05 Hz.
<span>0.0001 km / year or 10^-5 km/year just take 50 km and divide it by 5 million</span>